Literacy skills are critical for building science knowledge. For English Language Learners (ELLs)--the fastest growing population in U.S. schools (Goldenberg 2008)--learning English compounds the challenge of learning complex science concepts. This challenge is particularly acute for learning academic, science-specific English words and language structures as opposed to conversational English. The "Next Generation Science Standards" (NGSS Lead States 2013) are cognitively demanding and highlight the importance of science and engineering, so science teachers need effective instructional strategies to scaffold both student understanding and their use of science-specific language structures. A particular stand-alone science term is like a "brick" in the structure of students' understanding of science, and the language structures that connect the bricks are the "mortar" that holds the edifice of scientific understanding together (Dutro and Morgan 2001). These mortar words are general utility words and phrases required for connecting science vocabulary bricks and describing specific relationships. The "NGSS" emphasis on the three foundational dimensions--disciplinary core ideas, science and engineering practices, and crosscutting concepts--likewise highlights the importance of students' mastery of science-specific language structures to effectively learn these interrelated dimensions. In this article, the authors describe strategies that Eric Bookstrom, with support and collaboration with the other authors, used to teach scientific language structures to first-year high school ELLs--though the same or modified strategies would work well in any classroom.